<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div class="box">
      <div class="erweima"></div>
    </div>
    <script>
      //父节点 parentNode
      var erweima = document.querySelector(".erweima");
      //得到的是离元素最近的父级节点 找不到就返回为空null
      console.log(erweima.parentNode);
    </script>
  </body>
</html>
